To understand the cellular events which lead to the expression of malignancy and the escape of cancer cells from successful destruction by the immune system, it is important to investigate the surface chemistry and supramolecular organization of their plasma membranes. Using a combination of recently developed electron-microscopic techniques, I plan to study the plasma membranes of normal and transformed cells in culture to determine alterations in surface chemistry, molecular organization, and component mobility which may be characteristic of the malignant state.